With the miniaturization of semiconductor devices, it is becoming difficult to form resist patterns with sufficient lithography margins. Thus, when manufacturing a photomask, the pass or fail of mask pattern data is verified in advance by a lithography compliance check (LCC) or the like, and a photomask is manufactured using mask pattern data having passed the LCC.
A conventional LCC obtains an optical image within a resist by using mask pattern data, exposure conditions, and process conditions (resist film thickness and the like). At that time, the optical image is averaged in a resist film thickness direction. A dimension of a resist, when viewed from a top surface side of a resist pattern, is derived using the optical image obtained in this way, and the pass or fail of the mask pattern data is determined based on the dimension of the resist.
However, in such an LCC, a slope of a collapsed resist pattern or the like could not be checked. As a result, until the resist pattern is actually formed, poor formation of the resist pattern could not be verified. Therefore, it is desired to accurately determine the quality of the mask pattern data.